Due to the increasing expense of wood, the prior art has sought to construct pallets for use in material handling from alternate materials such as plastic or compressed paper, wood chips and wood pulp. Examples of prior art pallets constructed from various types of composite materials are illustrated in the Carlson U.S. Pat. No. 3,359,929, issued Dec. 26, 1967; the Sullivan U.S. Pat. No. 3,199,469, issued Aug. 10, 1965; the Addy U.S. Pat. No. 3,433,184, issued Mar. 18, 1969; and the Lawlor U.S. Pat. No. 3,762,342, issued Oct. 2, 1973. Other examples are shown in the Wharton U.S. Pat. No. 3,702,100, issued Nov. 7, 1972; the Monroe U.S. Pat. No. 3,720,176, issued Mar. 13, 1973; and the Hoffman U.S. Pat. No. 3,611,952, issued Oct. 12, 1971.
Attention is also directed to the Fleming U.S. Pat. No. 4,145,974, issued Mar. 27, 1979; the Rosewicz U.S. Pat. No. 4,029,023, issued June 14, 1977; the Sullivan U.S. Pat. No. 1,922,560, issued Aug. 15, 1933; the Geimer U.S. Pat. No. 4,061,813, issued Dec. 6, 1977; and German Offenlegungsschrift No. 27 32 373.
Attention is further directed to the Caughy U.S. Pat. No. 4,248,163 assigned to the assignee of the present invention. That patent describes the construction of high strength durable pallets comprised of wood particles intermixed with a binder and compressed in a suitable press. The pallet shown there provides a particularly high strength and durable pallet which is stackable with other similar pallets and adapted to receive the forks of fork lift trucks in any of four directions.
In some applications of pallets, such as in supporting stacks of roofing materials or paper, the loaded pallets are stacked one on top of the other, with the feet or legs of an upper pallet resting upon the material supported on the pallet immediately below. In some cases, the feet of the upper pallet may "print" that material, i.e. leave an undesirable impression therein.